in the long run maybe :) the plan is to port the mmx stuff to c (c++) first and to add a general x-window output object (right now, only xv), so it at least works for all linux targets.
i'm afraid these are the strengths of PDP and that xv is much faster than a general X-window output. You don't have to remove xv, it's now in the official XFree86.
also, these are the reasons why i got into PDP and not in GEM, because it can run with a decent framerate on an ordinary machine, e.g. not hardware accelerated.
cheers,
sevy/yves